A firefighter wannabe claims the FDNY unfairly rejected his application over his hitting on a customer and cursing out a boss at previous jobs — but that the department has welcomed less qualified candidates and even convicted felons.

Gregory Sajous, 32, received his rejection letter in October 2016. He lost an appeal in January.

Now he’s suing the city, whining that the FDNY determined he “lacked satisfactory character” for the job based solely on his “private-employment history.”

His suit only mentions he had “anger issues and [was] immature in the past,” but has since improved his “character.”

It neglects to mention the Bronx resident cycled through 23 jobs in just 13 years, according to a January 2017 letter from the Fire Department.

In 2011, Sajous was canned from a pantry-worker position with Starr Restaurants after he “gave his number to a client he was interested in” and she told his supervisor, according to the letter.

Then, in 2012, he was fired from another restaurant gig after arguing with a parking-lot security guard, the letter states.

In 2015 he was terminated from his housekeeper job at Brookdale Hospital for cursing out a supervisor, he admitted in his appeal.

Sajous’ “extensive negative employment history demonstrates he lacks the good character required for the position of firefighter and raises serious concerns about his ability to carry out the duties of a firefighter,” FDNY lawyer Rosharna Hazel wrote in the letter.

Still, Sajous says in court papers that the department brought on people with “much more serious histories of misconduct.” He cites one candidate who was convicted of assault and another with an arrest history including burglary.

Sajous’ own Facebook page suggests he’s no role model. It features photos of him hugging a stripper, a doctored image of Barack Obama giving President Trump the middle finger and a shot of three bottles of Pure White Hennessy on a bed.

He’s suing for a determination that he’s eligible to become a firefighter plus back pay.